Related papers: Hydrogen deficient donors in low-mass X-ray binari…
I review the energy spectra of low mass X-ray binaries (LMXBs) containing weakly magnetized accreting neutron stars (NS), emphasizing the most recent broad band (0.1-200 keV) spectral and timing observations performed by Beppo-SAX and RXTE.…
We present studies of the collapse of neutron stars that undergo a hadron-quark phase transition. A spherical Lagrangian hydrodynamic code has been written. As initial condition we take different neutron star configurations taking into…
We present 15 high mass X-ray binary (HMXB) candidates in the disk of M31 for which we are able to infer compact object type, spectral type of the donor star, and age using multiwavelength observations from NuSTAR, Chandra, and the Hubble…
The oscillation of neutrons $n$ into mirror neutrons $n'$, their mass degenerate partners from dark mirror sector, can have interesting implications for neutron stars: an ordinary neutron star could gradually transform into a mixed star…
What are the most important conditions and processes governing the growth of stellar-origin compact objects? The identification of compact object type as either black hole (BH) or neutron star (NS) is fundamental to understanding their…
We consider the merging of high-mass black-hole binaries of the Cyg X-1 type, in which the O-star companion becomes a neutron star following a supernova explosion. Our estimated rate of mergers, $\sim 2\times 10^{-5} yr^{-1}$ for the…
We suggest that high-mass black holes; i.e., black holes of several solar masses, can be formed in binaries with low-mass main-sequence companions, provided that the hydrogen envelope of the massive star is removed in common envelope…
Before the launch of the Rossi X-ray Timing Explorer (RXTE) satellite, the differences in the rapid X-ray variability between the two main types of neutron star binaries (i.e., the Z and atoll sources) could be explained by invoking…
We calculate the first dynamical evolutions of merging black hole-neutron star binaries that construct the combined black hole-neutron star spacetime in a general relativistic framework. We treat the metric in the conformal flatness…
Hydrodynamic simulations of the merger of stellar mass black hole - neutron star binaries (BH/NS) are compared with mergers of binary neutron stars (NS/NS). The simulations are Newtonian, but take into account the emission and backreaction…
Can one distinguish a binary black hole undergoing a merger from a binary neutron star if the individual compact companions have masses that fall inside the so-called mass gap of $3-5\ M_\odot$? For neutron stars, achieving such masses…
We consider constraints on the formation of low-mass X-ray binaries containing neutron stars (NLMXBs) arising from the presence of soft X-ray transients among these systems. We show that in short-period systems driven by angular momentum…
Cataclysmic Variables are a distinct class of interacting binaries, transferring mass from a donor star to a degenerate accretor, a white dwarf. We here review X-ray observations of these systems, with some emphasis on what has been…
A substantial fraction of the known neutron stars resides in X-ray binaries -- systems in which one compact object accretes matter from a companion star. Neutron stars in X-ray binaries have magnetic fields among the highest found in the…
In neutron star and black hole X-ray binaries the transitions between the two spectral states, hard and soft, signals the change between accretion via a hot advection-dominated flow(ADAF) and disk accretion. In a few cases the hard/soft…
Precise knowledge of the features of several X-ray sources from compact binary sources to galactic nuclei is gradually unveiling the physical parameters of relativistic neutron stars and black holes therein. Recent developments in theory,…
Recent progress in the understanding of the high density phase of neutron stars advances the view that a substantial fraction of the matter consists of hyperons. The possible impacts of a highly attractive interaction between hyperons on…
We discuss mass transfer in eccentric binaries containing a white dwarf and a neutron star (WD--NS binaries). We show that such binaries are produced from field binaries following a series of mass transfer episodes that allow the white…
In close binary systems composed of a normal, donor star and an accreting neutron star, the amount of material received by the accreting component is, so far, a real intrigue. In the literature there are available models that link the…
The accretion of ~ 0.1 -- 1 M_o of material by a neutron star through Roche lobe overflow of its companion or through white-dwarf/neutron-star coalescence in a low mass binary system could be enough to exceed the critical mass of a neutron…